I'm tall for a woman, and people are constantly commenting on it: "Wow, you're really tall!"
"Do you play basketball?"
"How tall ARE you?"
The worst is when it's an insecure guy and he starts actually ARGUING with me about my height: "I'm 6'0". There's no way you're 6'0" because you're taller than me. You must be at least 6'3"!"
Um, no.
It used to REALLY bother me when I was younger. Now I'm just over it, and I've given up on witty comebacks. Usually just a silent, disinterested nod makes them stop. I don't know why people think it's okay to comment on other people's appearance. If they really feel the need to talk and can't think of anything else to say, they should just restrict their remarks to the weather.